It has been demonstrated that an animals' behaviour can be altered by exposure to extremely low frequency (ELF) magnetic fields. This includes navigation, migration and homing in birds, insects and newts (Deutschlander et al, 1998) and alteration of opioid-induced analgesia in molluscs, birds and rodents (Betancur et al, 1994). There is also evidence that extremely low frequency magnetic fields have effects on behaviour in humans (Thomas et al, 1998; Papi et al, 1995). Increasing evidence suggests that pulsed ELF fields, also called Cnps, can be used for both therapeutic (Thomas et al, 1998) and diagnostic (Thomas et al, 2000) purposes. However, the magnetic field intensities required for diagnostic and treatment uses are approximately 40 to 200 μT, a magnetic field intensity similar to the Earth's magnetic field. The electric power required to generate fields of such intensity is very large and requires a fixed and relatively expensive apparatus.
Recent experiments have demonstrated that under ELF magnetic field shielding, rodents could sense the absence of weak (<0.1 μT) ELF fields (Del Seppia et al, 2000). Stress-induced analgesia appeared to be attenuated or abolished in mice placed in a magnetic field shielded box where there is an absence of ambient ELF fields when the wide-spectrum geomagnetic field is effectively zeroed. Under geomagnetic shielded conditions, animals appeared sensitive to weak ELF magnetic fields. Under shielded conditions, the behaviour of mice was modified by the absence of an ELF magnetic field of 0.1 μT intensity compared to a nominal 10-100 μT MF needed to modify behaviour (Choleris et al, 2001).
It has also been demonstrated (Kavaliers and Ossenkopp, 1993) that exposure to ELF magnetic fields (circa 100 μT) can attenuate opioid-induced analgaesia. Paradoxically, it has been suggested that daily repeated exposures to such ELF fields may induce analgesia (Kavaliers and Ossenkopp, 1985, 1993).
The Applicant has now developed a method involving daily repeated exposures to reduced ambient fields to induce analgesia in humans for clinical use. The Applicant has demonstrated that analgesia may be effectively achieved in humans by daily repeated exposures in a magnetically shielded room. Analgesia of individual body parts may also be surprisingly achieved by repeated magnetic shielding of that part or of a related anatomical target implicated in the creation of the pain, i.e. a related pain center, as alternative to shielding the entire body within a magnetically shielded room.
The Applicant has demonstrated that pulsed ELF fields of approximately 100 μT may be generated within a portable, battery-operated device that can effectively provide intensity fields to a specified, location in order to alleviate a variety of disorders. Lower intensity fields may also be effectively utilized with simultaneously shielding of the target tissue from external ambient ELF fields including the Earth's geomagnetic field. This renders portable ELF and pulsed ELF magnetic field therapy devices useful for both diagnosis and treatment of disease.